Valley fire departments, with assistance from one Hollywood legend and one harrowing film, are lending a helping hand to firefighters in Detroit this weekend.

The Michigan city’s firemen battle an average of 30 structure fires everyday, fighting against one of the world’s highest arson rates in its blighted neighborhoods. Since its heyday in the 1950s, Detroit’s population has dropped from 1.8 million people to 713,000. There are an estimated 80,000 abandoned buildings there, with more burning every day.

The task of fighting those fires falls to the under-funded, under-equipped and resource-strapped Detroit Fire Department. Two filmmakers embedded with firefighters there for more than a year to make the new documentary, “Burn: One Year on the Front Lines of the Battle to Save Detroit.”

The film screens on Saturday, April 6 at the Wheeler Opera House, in an event sponsored by the fire departments from Aspen, Basalt, Snowmass and Carbondale. Proceeds from the benefit will go to funding equipment for the Detroit Fire Department, through the Leary Firefighter Foundation.

“We’re so used to having the equipment we need when we need it,” said Aspen Fire Chief Rick Balentine. “They’ve got guys with duct tape on their turnout boots — just stuff we can’t imagine.”

Robert Wagner, the actor and Aspenite, who grew up in Detroit, will introduce the film. Known to one generation as the hunky star of “Hart to Hart” and another as Number Two in the “Austin Powers” trilogy, Wagner praised the film for capturing the seemingly hopeless plight of his hometown and its firefighters.

“It’s just so real,” Wagner said in an interview at the Aspen fire station, donning an “AVFD” baseball cap. “Everybody’s so relaxed. You can tell they got used to having the cameras around for a long time.”

The film’s producer/directors, Tom Putnam and Brenna Sanchez, spent 13 months with Detroit’s Engine Company 50, based on the city’s east side. They were drawn to the story after a veteran firefighter was killed in 2008, fighting a blaze in an abandoned home.

“They deserve a lot of credit for making this picture,” said Wagner. “And I think if we can make people aware of it, people will respond very positively to it.”

While the film offers an intense, insider’s look at firefighting in a nearly post-apocalyptic environment, Wagner said it’s also a cautionary tale for American cities. He’s seen Detroit go from its past as the booming economic center of the automobile industry to its abandoned and economically depressed present.

“At one time it was the Paris of the midwest,” he said. “The city’s been cut in half. It’s very frightening to see that, because it could happen anywhere.”

Seed money for the film came from charitable donations, and to benefit the Leary Firefighters Foundation, a nonprofit that provides equipment and training for under-funded firemen nationwide. Aspen Fire’s relationship with Leary goes back to 2005, when local firemen joined the nonprofit in relief efforts and firefighting assistance in New Orleans in the aftermath of Hurricane Katrina.

When Chief Balentine heard about “Burn,” he saw another opportunity for Aspen to assist firefighters in need by partnering with Leary.

“Our department in Aspen has always been ready and willing to help other fire departments,” said Balentine. “I’m a firm believer that what goes around comes around.”

Along with their work in New Orleans, Balentine and local firefighters have done ride-alongs with metropolitan firefighters in cities like Houston. Balentine has made it a department priority to use the valley’s resources to help firefighters elsewhere.

“You never know, we may need help next time,” he explained. “So building bonds with other fire departments — whether it’s in the next county, the next state, or across the country — is invaluable for us.”

Aspen firefighter Bruce Bradshaw said the film and the passionate firefighters of Detroit have been an inspiration.

“What I’m impressed with is there’s been paycuts, layoffs, pensions gone, their equipment is falling apart, they can’t get their trucks serviced, they’re going into these massive fires, and they’re still sticking it out,” he said. “That just blows me away.”

Saturday’s screening begins at 7:30 p.m. It will be followed by a live Skype interview with a firefighter featured in “Burn.” Tickets are $15 at detroitfirefilm.org.